Power management system

1. A power management system comprising: a system controller configured to receive load-related information data including power requirement of a load and storage battery-related information data including state of a storage battery assembly including a plurality of storage batteries and to create an overall charge-discharge control instruction for an entire power management system based on the load-related information data and the storage battery-related information data; a hierarchical charge-discharge control apparatus configured to receive the overall charge-discharge control instruction from the system controller and to perform charge-discharge control of the plurality of storage batteries, which are classified into a plurality of hierarchical levels, on a hierarchical level basis; and a plurality of power converters configured to perform electric power conversion among a power source electrically connectable to the power management system, the storage battery assembly, and the load, wherein the hierarchical levels of the storage battery assembly comprise: level of a storage battery unit including a predetermined number of storage battery packs arranged in an array, each storage battery pack including a plurality of storage battery unit cells; and level of a unit group including a predetermined number of storage battery units arranged and connected to each of the plurality of power converters, the unit groups correspondingly assigned to the plurality of power converters, respectively, the hierarchical charge-discharge control apparatus comprises: a master controller configured to receive an overall charge-discharge control instruction from the system controller and to create an assembly charge-discharge control instruction of the storage battery assembly based on the overall charge-discharge control instruction; and a power converter manager configured to receive the assembly charge-discharge control instruction and to perform charge-discharge control for each of the plurality of power converters by controlling charge-discharge of the storage battery units belonging to the unit group corresponding to each power converter.

2. The power management system of claim 1 , further comprising: a sub-controller configured to control charge-discharge of each of the storage battery units connected to the power converters controlled by the power converter manager.

3. The power management system of claim 2 , wherein the master controller receives power converter management data as state data of the power converters from the power converter manager, receives unit state data as state data of each storage battery unit from the sub-controller, determines whether the overall charge-discharge control instruction is executable, based on the received power converter management data and unit state data, and transmits the assembly charge-discharge control instruction to the power converter manager on the basis of a result of the determination.

4. The power management system of claim 3 , wherein the master controller transmits an activation check signal to check whether the system controller is in operation to the system controller at predetermined intervals.

5. The power management system of claim 4 , wherein each of the storage battery units includes a predetermined number of storage battery pack lines connected in parallel to one another, each of the storage battery pack lines including a predetermined number of the storage battery packs connected in series, and the sub-controller comprises a plurality of switches each of which is connected and placed between the corresponding power converter and one of the storage battery pack lines constituting each storage battery unit, and acquires pack state data as state data of each of the storage battery packs constituting each storage battery unit and controls operations of the switches on the basis of the acquired pack state data.

6. The power management system of claim 5 , further comprising: a storage battery power management apparatus configured to acquire the storage battery-related information data including the state data of the storage battery assembly; and a load power management apparatus configured to acquire the load-related information data on the power requirement of the load.

7. The power management system of claim 6 , wherein the sub-controller transmits the unit state data of each of the storage battery units based on the acquired pack state data to the master controller and the storage battery power management apparatus.

8. The power management system of claim 6 , wherein the storage battery power management apparatus receives the power converter state data as the power converter management data from the master controller, and sends the system controller the received power converter state data as the storage battery-related information, together with the unit state data transmitted from the sub-controller.

9. The power management system of claim 1 , further comprising a storage battery assembly including a plurality of storage batteries.

10. The power management system of claim 2 , further comprising: a fault determination unit configured to determine whether the master controller is faulty based on whether communication performed by the master controller remains abnormal for more than a predetermined threshold margin period; and a substitution unit configured to substitute the master controller with one of a plurality of the sub-controllers according to a predetermined substitute specifying criterion when the fault determination unit determines that the master controller is faulty.

11. The power management system of claim 10 , wherein the substitution unit uses a state of charge of each of the storage battery units managed by the sub-controllers as the substitute specifying criterion, and substitutes the master controller with the sub-controller in charge of one of the plurality of storage battery units having the highest state of charge.

12. The power management system of claim 10 , wherein the substitution unit uses a predetermined rotation order as the substitute specifying criterion and substitutes the master controller with one of the sub-controllers in a predetermined order of rotation at each predetermined substitution period.

13. The power management system of claim 3 , wherein the master controller changes the assembly charge-discharge control instruction according to state data of the plurality of power converters without changing the content of the overall charge-discharge control instruction and sends the assembly charge-discharge control instruction to the power converter manager.

14. The power management system of claim 6 , wherein the master controller comprises: a unit configured to calculate a storage battery replacement unit voltage which is a voltage of a replacement of unit storage battery on the basis of the unit state data transmitted from the sub-controller under the predetermined assembly charge-discharge control instruction and to calculate a voltage changing rate which is a change in the storage battery replacement unit voltage over charge-discharge elapsed time; and an abnormal storage battery detection unit configured to compare an average of the voltage changing rates of a plurality of the replacement units of storage battery with the voltage changing rate of each of the replacement units of storage battery and determine that a replacement of unit storage battery having the voltage changing rate exceeding a predetermined abnormal threshold changing rate difference is an abnormal replacement of unit storage battery.

15. The power management system of claim 6 , wherein the master controller comprises: a unit configured to use as a predetermined test charge-discharge control instruction the assembly charge-discharge control instruction, calculate a state of charge of a replacement of unit storage battery based on the unit state data transmitted from the sub-controller under the test charge-discharge control instruction, and calculate a state-of-charge change time which is the time taken for the state of charge to change by a predetermined state-of-charge range; and a deteriorated storage battery detection unit configured to compare a preset deterioration threshold change time with the state-of-charge change time of each replacement of unit storage battery and determine that a replacement of unit storage battery having the state-of-charge change time shorter than the deterioration threshold change time is a deteriorated replacement of unit storage battery.

16. The power management system of claim 7 , wherein each of the master controller and the sub-controller comprises: a failure determination unit configured to determine the presence of a failure of the storage battery power management apparatus based on whether data reception performed by the storage battery power management apparatus is normal; and a data organization unit configured to, when the failure determination unit determines that the storage battery power management apparatus has the failure, organize data not transmitted to the storage battery power management apparatus according to a predetermined data processing standards during a failure period thereof.

17. The power management system of claim 16 , wherein the data organization unit organizes the data by using, as the data processing standard, a standard specifying that data not transmitted to the storage battery power management apparatus is accumulated up to a predetermined limit of data storage capacity, and then is deleted in chronological order when the amount of data not transmitted to the storage battery power management apparatus exceeds the limit of the data storage capacity.

18. The power management system of claim 16 , wherein the data organization unit organizes the data by using, as the data processing standard, a standard specifying that the data is deleted in ascending order of predetermined data importance when the amount of data not transmitted to the storage battery power management apparatus exceeds the limit of the data storage capacity.

19. The power management system of claim 16 , wherein the data organization unit organizes the data by using, as the data processing standard, a standard specifying that the data is accumulated in a newly provided backup memory device in chronological order when the amount of data not transmitted to the storage battery power management apparatus exceeds the limit of the data storage capacity.

20. The power management system of claim 16 , wherein the data organization unit organizes the data by using, as the data processing standard, a standard specifying that the data is, in chronological order, transmitted to and stored in a memory device of the system controller, when the amount of data not transmitted to the storage battery power management apparatus exceeds the limit of the data storage capacity.